Self-retaining jointed rule.



Patented Nov. 26, I901.

W. THOMAS & .1. E. SPARGO.

SELF RETAINING JQJENTED RULE.

(No Model.)

WITNESSES. a mgm (Application filed Man 25, 1901.)

' lll lll 1 l o '1 |NVENTOR5 4 m: "cams PETERS c0, PHOTO-LXTNO, WASHINGTON. u, 0,

UNITED STATES PATENT OFFICE.

WILLIAM THOMAS AND JAMES E. SPARGO, OF BRIDGEPORT, CONNECTICUT.

SELF-RETAINING ,JOINTED RULE.

srnorrioArrolv forming part of Letters Patent No. 687,589, dated November 26, 1901. Application filed March 25, 1901. Serial No. 52,727. (No model.)

To all whom it may concern:

Be it known that we, WILLIAM THOMAS and JAMES E. SPARGO,Subj ects of the Kin gof Great Britain, residing at Bridgeport, county of Fairfield, State of Connecticut, have invented a new and useful Self-Retaining Jointed Rule, of which the following is a specification.

Our invention relates to ordinary jointed rules, and has for its object to so improve their construction that they may be conveniently used for measuring as far as the rule will reach in any direction, and the rule will be self-retaining when either half or wholly opened, no matter in what position it may be held.

It is of course perfectly well understood that jointed rules, even of the cheaper grades, when new are riveted tightly at the joints, so that the sections will remain in position. In practice, however, the joints quickly wear loose, and it is impossible to prevent them from wearing loose, so that, as a matter of fact, all jointed rules of ordinary construction, the better grades as well as the medium and cheaper grades, quicklybecome loose at the joints, so that if extended in any direction the sections will drop to. the closed position.

Our present invention enables us to provide a jointed rule of any grade, the additional cost of construction being so slight as to be hardly appreciable, which may be made relatively loose at the joints when new, thus avoiding the objectionable stifiness of all new rules, and which for practically an unlimited length of time will be self-retaining when extended in any'position in which it may he placed. This result we accomplish by providing both the central and the lateral'joints with a knuckle having bearing-surfaces and ,a spring bearing upon these surfaces in such a manner that any of the sections may be re tained either in the half-open or fully-open position, the action of the spring upon the bearing-surfaces of the knuckles resembling to a certain extent the action of the spring of a jackknife upon the heel of the blade. We are thus enabled to provide at a minimum cost rules which may be used as high or as far laterally in either direction as the user can reach without danger of the rule folding, and this'whether the rule be a new one or one that has been long in use or whether it be a high-priced rule or a medium or low priced rule.

In order to accomplish the desired result, we have devised the novel rule of which the following description, in connection with the accompanying drawings, is a specification, reference characters being used to designate the several parts.

Figure 1 is an elevation of our novel rule, showing the central joint in the closed position, and a back view of the two lateral joints in the open position; Fig. 2, a view, partly in section, showing the central joint in the halfopen position; Fig. 3, a View showing the central joint in the open position; Fig. 4, an edge view of the centraljoint; Fig. 5, an edge view showing one of the lateral joints in the closed position, and Fig. 6 is a similar view showing one of the lateral joints in the halfopen position.

The drawings illustrate an ordinary triplejointed rule.

A denotes sections connected by a central joint B, and C denotes end sections, which are connected to sections A byjoints D, which for convenience we term lateral joints. It is of course well understood that ordinary jointed rules of the type illustrated as produced by different manufacturers diifer greatly in details of construction and that different grades of rules produced by the same manufacturer differ in details of construction.

We wish it distinctly understood that our invention is not limited to any special make or style of joints, but is equally applicable to the various styles of joints made by different manufacturers in the various grades of jointed rules. By that we mean that the number, location, or relative thickness of the leaves or knuckles of the hinges or joints are not of the essence of our invention, but may be varied to an unlimited extent, the special requirements at each joint being that one member be provided with a leaf or knuckle E, having bearing-surfaces 10, 11, and 12 lying at right angles to each other, and that the other member be provided with a spring- 13, which is adapted to engage bearing-sunface 12 when the members are in the closed position, as in Figs. 1 and 5, to engage bearing-surface 11 when the members are in the half-open position, as in Figs. 2 and 6, and to engage bearing-surface When the members are in the fully-open position, as is the central joint in Fig. 3 and the two lateral joints in Fig. 1. In the drawings we have shown the knuckle E of each joint as located centrally. This, however, is not an essential feature of construct-ion, and, if preferred, two or more knuckles E-that is,knuckles provided with bearing-surfacesmay be used at the joints, although in practice we have found one knuckle E at each joint, placed centrally and made of medium Wid th, to be amply sufficient for the purposes of our invention. In Figs. 1, 2, and 3 we have shown the left section A as carrying the knuckle E and the right section A as carrying the spring 13. This spring is shown as located in a recess 14 in the member, the recess being made of suitable shape and size to give full play to the spring, which is retained in position by rivets 15, passing transversely through the section and through the shank of the spring. In practice we preferably round the angles of knuckle E of the central joint slightly, as at 16, .so as to permit the members to work freely, but still to retain them in position. \Ve also preferably provide the spring with a head 17, which lies in the outer end of recess 14 and extends to the back of the member, as is clearly shown in Figs. 2 and 4. This head serves as a cap to cover the end of recess 14 and to keep dirt and lint from a pocket out of the joint.

In Figs. 1, 5, and 6 we have illustrated the construction of the lateraljoints, so called, in which the knuckles E and the springs 13 are also located centrally of the joints. these joints we preferably do not round the angles of the knuckle, as in the central joint,

The springs lie in springs bend backward and resume their normal position when the'members are in either the open, half-open, or closed position. The springs 13 in the lateral joints are secured in position by rivets 15, the same as in the central joint, and the knuckles E of the lateral joints are shown as secured in position by similar rivets 18, which pass transversely through the sections, including the knuckles E and the other knuckles which comprise the joint.

Having thus described our invention, we claim- The combination with the sections of a jointed rule, of a knuckle E in each joint carried by one member and provided with bearin g-surfaces l yin g at right angles to each other and a spring carried by the other member and engaging said surfaces, said spring lying in a central recess in the section and being provided with a head recessed in the end of the section and extending to the edge thereof.

In testimony whereof we affix our signatures in presence of two witnesses.

WILLIAM THOMAS. JAMES E. SPARGO.

Witnesses:

A. M. W OOSTER, S. W. ATHERTON. 

